We distinguish two types of controls: swipe controls and switches. Non-limiting examples of swipe controls include variable capacitors and resistors which change their capacitance, respectively resistance as a knob is turned. Another non-limiting example of a swipe control is a computer mouse: as the mouse is moved a cursor on the screen moves. In swipe controls, a physical motion along some path is transformed into the continuous adjustment of some property or signal. A switch, by contrast, transforms a physical action into a binary state change or signal. A non-limiting example of a switch is the familiar electric switch for turning a light on and off. These types of controls are of an increasing importance in today's world, and there can be implementation and design issues concerning them.